6 links
ChemicalElements.com: Magnesium
chemicalelements.com
Basic information, atomic structure, and table of isotopes.
EnvironmentalChemistry.com: Magnesium
environmentalchemistry.com
Atomic structure, chemical and physical properties, and table of nuclides.
Lenntech: Magnesium
lenntech.com
Physical data, chemical properties, health and environmental effects.
Radiochemistry of Magnesium
lib-www.lanl.gov
Full text of the monograph by A. W. Fairhall (Dept. of Chemistry, University of Washington, Seattle, Washington). [PDF]
Wikipedia: Magnesium
en.wikipedia.org
Properties of the element, including its history, applications, and characteristics.